This invention relates to spray nozzles, and more specifically relates to a novel center vane for a straight-through solid cone spray type of nozzle.
Spray nozzles for forming solid spray cones are well known and are shown, for example, in U.S. Pat. No. 3,104,829 to Wahlin, U.S. Pat. No. 3,146,674 to Wahlin and 3,275,248 to O'Brien et al. Solid-spray solid cone nozzles are also commercially available from the Wm. Steinen Mfg. Co. of Parsippany, New Jersey, the assignee of the present application.
Solid cone nozzles commonly comprise a nozzle body having an input chamber which is connected to a fluid-conducting conduit of given diameter and flow capacity for fluids at a given pressure. A center vane is placed in the input chamber of the nozzle body and communicates between the input section and an axial discharge orifice of the nozzle body. The center vane commonly is provided with a plurality of slots which differ in number, angular configuration and size depending upon the desired end use and to maintain a solid spray cone in which the fluid flow per unit of time at any unit area across the cone is as uniform as possible relative to other unit areas across the cone.
In the past, the vane for the spray nozzle was custom-made for a particular application and to obtain a solid spray cone under given conditions of input pipe size, input pressure and volumetric fluid flow. It was not possible to simply change the scale of a given vane design when going from one input pipe size to another or from one input pressure to another because the resulting spray pattern would no longer be uniform and generally would become hollow or otherwise unsuitable. Thus a new vane design was required for each set of new pressure, volumetric flow and pipe diameter parameters. These vane designs are time-consuming since they are generally reached only after considerable trial and error methods and the cost of the resulting nozzle is substantially increased.
Parameters of the vane design which can be changed include the vane thickness, changes in the number of slots and their location, changes in the angular relationship of the slot to the axis of the vane, and changes in the cross-sectional geometry of the openings through the vane. For example, in the past, when the flow rate was increased, the vane design would be commonly modified by increasing the number of slots through the vane and/or by increasing slot width. Care had to be taken, however, since, if the slots became too wide or too numerous, fluid distribution over the area of the spray cone was poor. Similarly, if the number of slots became too great, the individual slot area was smaller and the slots were easily clogged by particulates carried in the fluid by other deposits from the fluid. Care also had to be taken during the design not to have the slots so large that the webs between the slots within the vane were structurally weakened to the point where they could easily fail during manufacture or in operation. Care also had to be taken to ensure against forming a hollow spray cone pattern.